Radio receiving system



April 11, 1933. A. DM 1,903,420

RADIO RECEIVING SYSTEM Filed Jan. 25, 1931 3 9 2, 9 I 4 1 1 1 I 10: 11 1: 10 211 2. H01 M M Q W l i- F is?) r t1 1 Juwc 3m Patented Apr. 11, 1933 UNITED STATES A N -i C I-1 B ALEX BADMA, or BUFFALO, NEW YORK RADIO RECEIVING SYSTEM- 7 Application filed January 23, 1931. Serial No. 510,816.

ative. The time thus expended is, of course,-

taken up to properly heat thecathodes of the valves to the proper electron emitting temperature by their respective filaments. To the general radio public however, this has been a source of annoyance andhas resulted in undesirable premature operation of the receiv-' ingset. It is an object of the present invention to reduce this interval to aminimum by providing a simple apparatus insertable in numerous receiving circuits which will not materially affect the operation of the circuits therein or the present type of standard equip ment used. This has been accomplished'by applying an abnormal voltage to the filaments of the valves when energizing the set, causing a sudden rise of temperature of the same with the accompanying heating of the cathodes and resulting energization of the output circuit. The output circuit thus rendered' operative in turn through energizing a suitable device such as a' relay immediately value. The entire operation has been found to consume but three or less seconds of time as compared to the fifty to sixty seconds in previoustypes of apparatus. f 7 Upon deenergization of the receiving apparatus the filament heating circuit is immediately changed by operation of the relayfrom a circuit operating at normal voltage to one operating at an abnormal voltage and the apparatusis thus prepared for its rapid heatin function for the next instance of its use. is the operation of this improvement is entirely automatic, it does not add to the number of the present manual controls of the usual receiving set and therefore does not acts and sets the filament voltage to normal" affect the simplicity of operation of the same.

In the drawing, the figure is a diagram showing a multi-stage' amplifier. wherein is incorporated the filament control unit of the present invention. f

The drawing shows a portion of a usual form of a multi-stage receiver incorporating the use ofthe well known heater type of audion valves-'1. The anode or plate 2 of each of the valves is connected to-the leadv 3 of the primary of its transformer 4:. The

opposite leads 5 of the primary'6 of all the transformers are connected to each otherby thewire 7 which inturn is connected to the wire 8. The Wire 8 is connected toythe'posi tive side of the source of B current through a relay device hereinafter more fully described. The leads 9 of the secondaries 1O ofthe transformers are connected tothe' grids v 11 of theirfrespe'ctive valves, while the leads 12 ofTthe sec'ondaries are connected to-thef cathodes 13 of the'same and to eachother. The negative'side of the B? potential is connected to the cathodes by the wire 14., The leads 15 of the filaments of the tubes are connected to each other by the wire 14 and the; leads 16 of thesame are similarly connected 7 by the wire 17 The structure set forth in the precedingdescription will be recognized by those skilled in the art as an. operative form of a'u'sual hook-up using the heater typevalvesandis utilized as anexemplary form as abasis for disclosing the principle of the invention as hereinafter de-y scribed. i I i The'above mentioned wire 8 is connected to the coil lead 18 of an electro-magnetic device 19; This device is preferably a suitable type of relay having a polarized core 20. The opposite coillead 18thereof is connected to the positive source of plate potential. A bridging condenser'23 is connected between. the leads 18 and-24 of the relay. The switch arm 20 of the relay is pivoted at 21 and-is connected through the wire22 to the wire 17 5 which connects the leads "15 of the filaments. Upon energization'ofthe plate circuit the" switch armwillbeattracted to the core of the relay-and upon deenergization of the plate circuit the switch-arm underassistance of the spring 25 will be positively moved outwardly from the relay.

When the switch arm is against the core it is maintained on a switch contact 26 and when in the latter position it is maintained against the switch contact 27. A transformer 28 is provided to supply the filamentpotential and has a primary suitably connected to a source of alternating Current potential and a secondary 29 capable/Of approximately a ten volt output. The end lead 30 of the secondary is connected directly to the wire 14: and the other end lead 31 is con nected to the contact 27 by the wire 32.. The

secondary is tapped with a lead 33 at approximately the two and one half volt output portion thereof and is connected to the contact 26 by the Wire 34. I

In operation when the receiver is deenergized the filaments will be connected toreceive thefull ten volt output of the transformer secondary 29 as the switch arm 20 the core 20 thereof and to contact the switcharm with the switch contact 26 thus disengaging the switcharm from the ten volt contact 27 and connecting the filaments with the two and one half volt lead of the transformer for normal operation of the receiver. It has been found that the above described device permits the full operation of the receiver within approximately three seconds of the application of power thereto. It has also been found that since the ten volt load on the filament through its control by the plate circuit is not permitted to cause excessive heating thereof, that such loading does not materially affect the life of the filament,

It is not intended to limit the invention to the specific use of a relay for the purposes specified as it will be apparent to those l skilled in the art that a number of electromagnetic devices may be substituted therefor to control the switch arm without departing from the spirit of the invention.

What is claimed is:

1. In a radio receiving system including an audion having a cathode and an anode filament to its source of potential, the combination of a source of reduced filament potential, a switch operable to connect either of the sources of potential tothe filament,

and electro-magneticmeans interposed in the anode circuit and operativeupon energization of the anode circuit to move said switch means to connect the source of reduced filament potential to the filament circuit, and said means when said anode circuit is deenergized moving'said switch means to con nect the first named source of potential to the filament.

2. In a radio receiving system including an audion having a cathode and an anode coupled respectively to an input and an output circuit, a heater filament for heating the cathode thereof, a source of filament poten-f tial, and a circuit connecting said source of potential to thefilament, the combination of means for varying the potential applied to said filament, operable to impress a relatively high voltage on said filament to quickly heat said filament to produce an electron flow from said anode, and to subsequently reduce said voltage to maintain continued electron flow from said anode. H

' 3. In a rad1o recelving system including an audion having a cathode and an anode coupled respectively to an input and an output circuit, a heater filament for heating the cathode, a source of filament potential, and

a circuit connecting said source of potential to the filament, the combination of means for automatically varying the potential applied to said filament operable to impress a relatively high voltage on said filament to quickly heat said filament to produce an electron flow from said anodeand to subsequently reduce said voltage to maintain con-;

tinued electron flow from said anode.

4. In a radio receiving system including an audion having a cathode and an anode coupled respectively to an input and an out-.

put circuit, a heater filament for heating the cathode, a source of filament potential, and

a circuit connecting said source of potential to the filament, the combination of control means for said source of potential, electromagnetic means interposed in the output circuit, said electromagnetic means being energized by the output circuit to operate said control means to first operate said filament at a relatively high potential and upon heating oi. the filament to an electron receiving temperature to subsequently cause said filament to be operated at a lower potential.

' ALEX BADMA.

coupled respectively to an input andan output circuit, a heater filament for heating the cathode thereof,'a source of filament potential and a filament circuit connecting the 

